Spraying apparatus



Feb. 9, 1 943. D. D. HEIMEURGE 2,310,633

SPRAYING APPARATUS Filed May 7, 1940 AIR Patented Feb. 9, 1943 staresresent oFFi cE 4 Claims.

This invention relates to spraying apparatus of a type popularly calledspray-guns. Such apparatus is now in general use for applying cleaningsprays to surfaces.

One of the objects of the invention is to provide a spray-gun apparatusof simple construction, so constructed that it will operate to produce athorough mixture of the ingredients constituting the spray as it leavesthe apparatus, or gun. A further object of the invention is to produceapparatus of this kind, particularly adapted for spraying a cleaningsolution upon surfaces to be cleaned, and to effect this through theagency of a compound stream of compressed air, gas, or steam and aliquid that operates automatically to entrain a cleaning solution.

A further object of the invention is to provide simple apparatus inwhich a single hand-controlled device will perform the function offorcibly spraying a cleaning solution upon the parts to be cleaned, andimmediately applying a rinsing wash to the same.

A further object of the invention is to provide a spraying device ofthis general character, which is so constructed that containers for acleaning solution can be quickly attached to the same, and at the sametime, to construct the device in such a way that the closure for thecontainer will be automatically opened when the same is secured inposition on the spraying device.

In the operation of the invention as'applied to a spraying device forspraying a cleaning liquid, the apparatus is so constructed that acompound. current composed of compressed air or gas, and water, isprojected through the barrel of the device. As this compound currentleaves the device, it entrains the cleaning solution. One of the objectsof this invention is to provide a construction for the device, whichwill enable it to automatically open the closure of the receptacle ofthe cleaning solution when this receptacle is secured to the device;also to provide a construction which will insure ample venting of theinterior of the cleaner fluid receptacle as the liquid within it isdrawn up into the expansion chamber or mixing chamber as the compoundcurrent issues from the device. I

A further object of the invention is to provide a container of simpleconstruction for carrying a solution to be used with a spraying devicein applying compressed air or gas for emitting a spray, and to constructthe receptacle in such a way that it can "be readily attached to the 55spraying device by inexpensive means carried in the cover of thereceptacle.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to bedescribed hereinafter, all of which contribute to produce an efficientspraying apparatus.

A preferred embodiment of the invention is described in the followingspecification, while the broad scope of the invention is pointed out inthe appended claims.

In the drawing:

Fig. 1 is a vertical section through a spraying apparatus embodying myinvention, but showing a portion of the body of the receptacle for'theentrained liquid, in elevation.

Fig. 2 is a View showing a portion of the muzzle of the device inelevation, and showing a portion of the same in section, together withthe upper end of the receptacle having a valve shown in section, whichwill be automatically opened when the receptacle is secured to thedevice.

In practicing the invention, I provide a body I, which preferablyincludes a handle 2 to be held in ones hand; and a barrel 3 that, ifdesired, may be detachably secured to a horizontal extension 4 thatprovides a threaded socket. The handle is provided with an inlet forcompressed air or gas, and also fora liquid such as water. In thepresent instance, the handle is provided with a longitudinal dividingpartition 5 carrying an air duct 6 and a water duct 1, the former ofwhich is preferably disposed in the forward part of the handle. Theseducts 6 and I are provided with inlets openings 8 and 9, at which an airhose i9 and a water hose ll may be attached. The ducts 6 and i may beprovided with transverse webs or walls [2, and I3, having ports 14through the same, which ports lead the air and the water laterally andrespectively through an air valve (not illustrated) having a port l5through which the air valve controls'the flow of the air back into theupper extension 611 of the duct 6. In a similar way, the water passesthrough a water valve (not illustrated) which delivers the water througha port l6 back into the upper extension 7a of the water duct 1.

I provide means for effecting a mixture of compressed air or gas, and aliquid, in the duct Ia. In order to accomplish this, I prefer to employan injector nozzle I! through which the compressed air flows so as to beprojected into a Ventu'ri ringor' sleeve 18,"theaxisbfwhiohissubstantially in line with the axis of the nozzle. This ring presents aduct with a constricted throat l9, and is formed with a flaring mouththrough which the water or other liquid is entrained. The other end ofthe ring has a flaring outlet 2| through which the compound currentcomposed of compressed air or gas, and the liquid passes into the bore22 of a barrel 33, and this bore 22 preferably tapers in the directionof flow to its outlet 24 where the diameter is restricted to a diameterthat should be smaller than the throat l9. By gradually reducing thecross-section in this way, the mixing efiect is enhanced. From thispoint the compound current issues into an expansion chamber, which alsooperates as a mixing chamber in which a cleaning solution is entrained.In order to adapt the action of the compound current to the particularrequirements of the liquid being entrained at this point, which might beadvisable where the liquid entrained would have a difierent viscosity, Iprefer to form the tipof the barrel 33 in the form of a removable nozzle25, and the end of this nozzle may be threaded onto the inner section ofthis barrel as shown. The inner end of the nozzle is formed with atransverse wall or head 26, through which an opening 21 is formed thatregisters with the outlet 24 from the conical bore 22. If desired,different nozzles 25 may be provided having difierent diameters for theinlet port or passage 21 of the same size or smaller than the outlet 24.This gives a certain amount of control of the action of the compoundcurrent when it expands into the expansion chamber or mixing chamber 28.This chamber 28 is preferably of tubular form, and the nozzle 25 simplyconstitutes an outer extension of the barrel. I

In the operation of the apparatus, the compound current flowing throughthe port 21 expands, so that the current assumes a more or less conicalform as indicated by the dotted lines 23, and the effect of this is todevelop a reduced pressure or partial vacuum at the inner portion of themixing chamber in the vicinity of the point indicated by the numeral 30.At or about this point I provide the nozzle or muzzle 25 with an inletpassage 3| at which the cleaning solution is entrained, and at thispoint the under side of the muzzle 25 is provided with a socket 32having a construction which will enable the outlet valve 33 of areceptacle 34, to be quickly attached. This is preferably accomplishedby providing bayonet slots 35 in the wall of the socket. The body of thevalve 33, which is rigidly secured to the cover 36 of the receptacle 34,is provided with outwardly projecting fingers 31 to cooperate With thebayonet slots. The

' valve 33 is provided with a valve closure in the form of a thick disc38 preferably of compressible material, which is held on its seat at the.valve outlet 39 through the agency of a coil spring 48, or similarmeans. This spring may thrust against a spring plate 4| at its upper end(see Fig. 2). When the receptacle is beingput in place, a central boss42 within the socket 32 will engage the valve closure 38 and move it offits seat. Suitable means is provided to insure that when the valve isoff its seat and the receptacle put in place as indicated at 3|,atmospheric air can find its way past the valve and back into the upperpart of the receptacle 34. In order to accomplish this, the disc 38 isof smaller diameter than the casing of the valve 33. The

eduction tube 43 for the liquid in the receptacle 34, is preferablysecured at its upper end in the valve closure 38, so that liquid drawnup the tube will pass through the disc 38 into the mixing chamber 28.

The relation of the parts when the receptacle is put in place, 'isclearly indicated in Fig. 1. This figure also illustrates the manner inwhich the valve casing may be secured to the cover 36. This isaccomplished by providing a threaded bushing 44 that receives a clampingnut 45 that clamps a soft packing disc or gasket 46 in position. Theedge of this gasket seats on the upper edge of the mouth of thereceptacle, so that when thecap 36 is screwed down tight, the receptaclewill not leak, and can be shipped to the point where it is to be used.The bushing 44 may be provided with internal threads to receive anadjustable plug 41, which can be adjusted in or out to regulate theforce of the spring.

The opening 48 through this plug around the eduction tube 43, gives someclearance so that the vent to the atmosphere past the edge of the openvalve closure 38, will be completed.

Of course, the lower end of the boss 42 presents a flat seat face toreceive the valve closure 38, and this makes a tight seal at this pointto prevent breaking the partial vacuum that is developed by the cone orfan developed by the compound current in the mixing chamber 28.

If desired, in practice, the receptacle 34 for the cleaning solution,may be made of inexpensive material, and the cover of each receptaclemay be provided with a valve similar to the valve 33; or, if desired, aplain cap similar to the cap 36 may be provided, having an internalthread 49 such as illustrated in Fig. l; and this cap may be removed andthe mouth of the receptacle screwed up into the cap 36.

Although I have illustrated the spray-gun as being used with a smallreceptacle that is attached to the gun itself, to be moved about withthe gun, it is obvious that if desired, the socket 32 could be attachedto an upper outlet on a large container, in which case the muzzle 25would be provided with a threaded tip 58 to which a hose could beattached for spraying the stream onto any surface that is to be cleaned;and this large container, with my attached apparatus could, if desired,be mounted on a wheeled truck, enabling it to be wheeled to any point ina garage or yard, where it is to be used.

While this device is obviously capable of many uses, it is expected tobe particularly useful in cleaning automobiles or in other situationswhere the parts to be cleaned are more or less inaccessible. Under suchcircumstances, the cleaning solution would be strong enough to effectthe loosening of grease or dirt, after which the parts could bethoroughly washed with clean water to remove all traces of the cleaningsolution, and prevent any chance that the cleaning fluid might causeerosion on metal parts to which it had been applied.

In the drawing, l5a and Mia indicate the location of hand-wheels foropening and closing these valves.

Due to the expansive power of the compressed air in the compound currentpassing through the expansion chamber, a very effective dispersion ofthe cleaning solution results in the cleaning jet issuing from the endof the muzzle. The use of this apparatus avoids the necessity forpreparing any large mass of cleaning water, and enables the apparatus tobe used instantly. when desired, for washing down pure water.

This apparatus gives a very nice control in operation, because theamount of the cleaning solution consumed will depend not only upon thevelocity of flow of the compound stream past the entraining duct 31, butalso upon the proportion of Water to the air, gas or steam in the.compound stream. These factors are controlled by the valves.

Many other embodiments of the invention may be resorted to withoutdeparting from the spirit of the invention.

What I claim is:

1. In a spray-gun apparatus, the combination of a body having a waterduct and a compressed air duct therein, an injector nozzle within saidbody, and a barrel substantially in alignment with the injector nozzleand cooperating with the nozzle to entrain water with the air flowingthrough the nozzle to form a compound current in the barrel composed ofthe compressed air and the water, said barrel having a mixing chambertapering toward its outlet end, and said barrel having an expansionchamber at said outlet end in which the compound current expands, saidexpansion chamber having a transverse wall presenting a fiat face on itsside that is located toward the outlet of the barrel, said transversewall having a centrally located relatively small inlet opening ascompared with the area of said transverse wall, so that as the compoundcurrent issues through the last-named inlet opening, it expands towardthe outlet of the barrel so as to develop an annular space around thesaid inlet and adjacent the said transverse wall where a reduction inpressure occurs, the side of said barrel having a minute opening throughthe same leading into the expansion chamber adjacent said transversewall and at said annular space, for admitting a cleaning liquid to beentrained into the compound 1 current flowing through the expansionchamber.

2. In a spray-gun apparatus, the combination of a body having a ducttherethrough for compressed air or gas, and having a duct therethroughfor conducting a liquid, injector means within the body, including anozzle and means having a duct into which the nozzle projects, fordeveloping a compound current composed of the compressed air or gas andthe liquid, said body having a tapering mixing chamber into which thegas and liquid pass from said duct,

and having a gradually reduced cross-section in which the elementscomposing the compound current become mixed, said body having anexpansion chamber beyond, and distinct from, the mixing chamber, intowhich the compound current from the mixing chamber issues, and in whichthe compound current expands as it flows through the body; and means foreffecting the entrainment of a liquid into the expansion chamber by thecompound current flowing therethrough.

3. In a spray-gun apparatus, the combination of a body having an inletfor a liquid, and a compressed air inlet, im'ector means within the bodyincluding an air nozzle, and a Venturi duct having a port therethroughcooperating with the air nozzle, and enabling the compressed air toentrain the liquid, said body having a mixing chamber receiving the airand liquid from the Venturi, in which the air and liquid mix, said bodyhaving an expansion chamber with an inlet at its rear end, with respectto the direction of flow, for admitting the compound current of air andliquid from the mixing chamber, said lastnamed inlet being of smallerarea than the Venturi port, the mixture of air and liquid operating toexpand and form a substantially conical jet within the expansionchamber, the said jet impinging on the inner face of the circumferentialwall of the expansion chamber adjacent to the outer end thereof, andthereby developing a partial vacuum in the rear end of the expansionchamber, the rear end of the expansion chamber having an inlet forinducting a second liquid into the compound current.

4. In a spraying apparatus, the combination of a barrel having anexpansion chamber through which water passes, said barrel having asocket on its under side, a container for cleaning solution, a valvemeans in the outlet of said container, means on said socket for securingsaid socket to said valve means, means associated with said socket forholding the valve means open, said valve and socket means constructedand arranged to provide a clearance around said securing means and valvemeans when the latter is in open position, to admit atmospheric air tothe interior of the container while the cleaning solution is beingwithdrawn therefrom.

DOUGLAS D. HEIMBURGER.

